Selectable seal cannula

Abstract

A surgical cannula with selectable seals which assure a fluid-tight fit around medical devices of a variety of sizes. The cannula includes a tubular member insertable into a medical patient and having a side wall defining a lumen through which a medical device may be inserted. The cannula also includes a housing mounted to a proximal end of the tubular member wherein the housing has a passage allowing insertion of a medical device therethrough and into the lumen. A movable member is mounted to the housing and is selectively movable between a first position and a second position across the passage. When the movable member is in its first position the passage accommodates insertion of a first medical device having a first outer cross-sectional dimension. A first valve body is mounted in the movable member and has a first opening therein corresponding in size to the outer cross-sectional dimension of a smaller second medical device, wherein the first opening is smaller than the passage. When the movable member is in its second position the first valve body provides a fluid tight seal around the second medical device.

I claim: 
     
       1. A surgical cannula, comprising: a tubular member insertable into a medical patient and having a side wall defining a lumen through which a medical device is to be inserted;   a housing mounted to a proximal end of said tubular member, wherein said housing has a passage allowing insertion of a medical device therethrough and into said lumen;   a movable member mounted to said housing and selectively movable between a first position, a second position and a third position across said passage, wherein when said movable member is in said first position said passage accommodates insertion of a first medical device having a first outer cross-sectional dimension;   a first valve body mounted in said movable member and having a first opening therein corresponding in size to an outer cross-sectional dimension of a smaller second medical device, wherein said first opening is smaller than said passage, and wherein when said movable member is in said second position said first valve body provides a fluid tight seal around said second medical device; and   a second valve body mounted in said movable member and having a second opening therein corresponding in size to an outer cross-sectional dimension of a smaller third medical device, wherein said second opening is smaller than said first opening, and wherein when said movable member is in said third position said second valve body provides a fluid tight seal around said third medical device.   
     
     
       2. The cannula of claim 1 and further including a separate elastomeric fixed valve body mounted in said housing and providing a fluid tight seal across said passage when no medical devices are inserted through said passage. 
     
     
       3. The cannula of claim 2 and further comprising a side port into said housing, wherein said side port is mounted to said housing between said tubular member and said fixed valve body, and wherein said side port has an on/off valve therein to allow selective fluid flow control through said side port. 
     
     
       4. The cannula of claim 3 wherein said passage comprises a circle at least ten millimeters in diameter, wherein said first opening is a circle about five millimeters in diameter, and wherein said second opening is a circle about three millimeters in diameter. 
     
     
       5. The cannula of claim 4 wherein said movable member has a gasketless hole therein to accommodate insertion of the first medical device when said movable member in said first position. 
     
     
       6. The cannula of claim 5 wherein said movable member is transversely slidably movable with respect to the passage of said housing. 
     
     
       7. The cannula of claim 1 and further comprising a side port into said housing, wherein said side port has an on/off valve therein to allow selective fluid flow control through said side port. 
     
     
       8. The cannula of claim 1 wherein said movable member has a gasketless hole therein to accommodate insertion of the first medical device when said movable member in said first position. 
     
     
       9. The cannula of claim 1 wherein said movable member is transversely slidably movable with respect to the passage of said housing. 
     
     
       10. The cannula of claim 1 wherein said movable member is rotatably movable with respect to said housing. 
     
     
       11. The cannula of claim 5 wherein said movable member is rotatably movable with respect to said housing. 
     
     
       12. The cannula of claim 1 wherein said passage comprises a circle at least ten millimeters in diameter, wherein said first opening is a circle about five millimeters in diameter, and wherein said second opening is a circle about three millimeters in diameter.